Switching device of a two-stage planetary gear

ABSTRACT

A two-stage planetary gear drive,-shifting device having an input shaft ( 1 ) which is connected with a sun gear ( 12 ) and an output shaft ( 2 ) which is connected to a planetary gear carrier ( 15 ), hollow internal gear ( 18 ), of the planetary gear drive, is form-fit, by a slide collar ( 19 ), to either a gear drive housing ( 3 ) or is coupled to the gear ( 12 ). The slide collar ( 19 ), is coaxial with the input drive shaft and is slidable into various shift positions by an electrical positioning member ( 31 ). It is proposed that the electrical positioning member ( 31 ) is an electromagnet, and an armature ( 33 ) of the electromagnet is connected, in a driving manner, with the slide collar ( 19 ).

FIELD OF THE INVENTION

The invention concerns a switching device of a two stage planetary gear.

BACKGROUND OF THE INVENTION

A basic, generic form of shifting devices was made known) from theoperating specification 4161 758 002b for two-stage shifting devices for“AC and DC Main Spindle Drive, 2K10, 2K12, 2K15, 2K20” of the ZFMaschinenantribe, GmbH, February, 1994. The gear drive has been mainlyused in tool machine drives for turning, milling, and machining centeredIndustries. DC/AC-main spindle motors serve as primary driving means.The gearing sets increase the band width of application of the mainspindle motors by increasing the flexibility of the tool machines in theworking of various starting materials, that is, by increasing cuttingpower through high torques or speeds of rotation. The two ratio changestages are formed, in that first, the input shaft, which is connected toa sun gear, is also coupled to a hollow internal gear and second, thesaid hollow gear is coupled with the housing. A planetary gear carrieris attached to the output shaft.

A sliding collar serves as an axially movable connection piece betweenthe internal gear and the sun gear, which is to say, between theinternal gear and the housing. This said collar is connected by means ofa forked switching member with an electrical limit switch unit. Thisencompasses a helical drive land a slip clutch and is driven by a directcurrent motor, which is placed axis-parallel to the input shaft andextends at the end above the gear drive housing. The helical driveconverts the rotating motion to a vertical movable shifting shaft, whichby means of a pinion and toothed bar, converts the rotating motion intoa linear movement. This is transmitted over a shifting element to thesliding collar. For the recognition of end-positions, two limit switchesserve In the circuit unit, which must be installed in the wiring,together with the end position detent. The shifting equipment is complexand expensive and It Is difficult to adjust this to match spatial anddrive aspects of application requirements.

Further, from DE 196 28 642 C2, an electro-mechanical shifting mechanismfor change of gear transmissions for motor vehicles is made known,wherein an armature of an electromagnet acts upon a slide collar bymeans of a shifting disk serving as a linkage lever. The shifting diskcan be placed in several shifting positions by means of a lockingmagnet. The activation rod of the armature can also coact directly on afork of the slide collar.

From DD 33 668, especially for motor vehicles, there is made known anelectromechanically controlled shifting apparatus for gear changetransmissions. Two springs center a gear shifting member into its middleposition by means of two armatures of two electromagnets. Byappropriate, varying control of the electromagnets, two other shiftlanes can be preselected and positioned. Since the electromagnets, whenin the switched-on condition, work against two springs, the currentdemand in the ON-condition is substantial and the efficiency is notsatisfactory.

Thus the invention has the purpose, of creating a simple shiftingapparatus, which, without great expense can be adapted to variousapplications and operational conditions.

SUMMARY OF THE INVENTION

In accord with the invention, the positioning member is anelectromagnet, the armature of which is driveably connected to a slidecollar. Since the electromagnet, in comparison to a helical gear drive,possesses no inherent friction, it is advantageous that theelectromagnet does possess detent means, which lock the armature in theshifting positions. These detent elements can be spring loaded ballelements. In order to increase the security, it is of advantage however,if locking magnets be employed as detent elements, by means of which, aform-fit secured position can be obtained.

The electromagnet is advantageously installed on the periphery of thegear drive housing, axis-parallel to the input shaft and to thedirection of shifting. Its length should not extend beyond the housingof the narrowly built planetary gear arrangement, so that the gear drivecan be conflict with electromotors of different diameters which, in somecases can extend beyond the cross-sectional contour of the gear drivehousing. Further, with an electromagnet, short shifting times can beobtained.

In accord with an embodiment, between the electromagnet and the slidecollar, a two-armed lever is provided, which is pivotally fastened inmid-section to the gear drive housing and is connected by one arm to thearmature and with the other arm on the slide collar. By means ofdifferent lever arms, the shifting force and the shifting path can bemodified. When this is done, it is advantageous, to place an adapterpiece between the gear drive housing and the electromagnet, in which thelever is secured. Thereby, the range of variation of the leverrelationships can be clearly increased.

In order to reduce the friction between the lever and the slide collar,it becomes necessary that the said slide collar has an outer and aninner part. The outer part is affixed by a an axial guide bolt to resistturning, and is guided axially to slide on the gear drive housing andprovided with a roller bearing to be pivotally secured on the innerpart. Thus there exists between the lever and the outer part of theslide collar no rotational movement between them, which could act uponthe shifting force. The inner part, which is compelled to execute theaxial movement, possesses an outer coupling toothing for coupling ontothe gear drive housing and an inner toothing for a driveable connectionwith the sun gear.

Since the electromagnet is inclusive of a limit detent, the end limitswitch can be dispensed with and need not be installed again. By meansof these measures, improper positioning and possibilities of error onthe part of the end user are avoided. For security, it is, however ofadvantage, to provide an end limit switch to monitor the shift positionand the shift functioning, although these need not be adjusted.

BRIEF DESCRIPTION OF THE DRAWING

Further advantages are more obvious in the following description basedon the drawing. In the drawing is presented an embodiment example of theinvention. The description and the claims contain a multitude offeatures in combination. The expert can advantageously examine theindividual features which can be brought together in furthercombinations.

The single FIG. 1/1 shows a partial longitudinal section through a twostage planet gear with a shifting device in accord with the invention.

DETAILED DESCRIPTION OF THE INVENTION

The two stage planetary gear possesses an input shaft 1 and an outputshaft 2, which are placed within bearing coverings 4 and 5 of a geardrive housing 3 and borne in roller bearings 6, 17. To the planetarygear belongs a sun gear 12 which is in a drive connection with the inputshaft 1. The sun gear 12 meshes with the planet gears 13. These aresupported by planetary bolts 14 in a planet gear carrier 16, which, hasa form-fit binding 16 with the output shaft 2. The a roller bearing 42in the housing 3 and is form-fit as well as rotatably bound to acoupling element 41. The coupling element 41, by means of an externallytoothed coupling 44, non-rotatably connected with an inner component ofslide collar 19. An outer part 20 of a slide collar 19 is supported onthis coupling element 41 by means of a roller bearing 22. The outer part20 is axially slidable relative to the gear drive housing 3, by guidanceof a bearing bolt 23, whereby the axial sliding of the said outer part20 is transferred to the inner part 21 by means of the roller bearing22.

The slide collar 19 can assume three shift positions. These positionsare a neutral position, a first shift position, in which the internalgear 18, by a coupling toothing 43 is attached to the housing 3, and asecond shift position, in which the said slide collar 19 couples theinternal gear 18 to the sun gear 12 by means of a coupling component 8with a come-along toothing 40 and a form-fit connection 11. A detent 7on the coupling component 8 limits the axial slide movement of the slide19.

The coupling component 8 is non-rotatably connected with the input shaft1 by means of a groove 9 and a spring 10. On the outer part 20 of theslide collar 19 is linked a lever 25, in which a forked end of an innerarm 26 of said lever 25 encompasses a transverse pin 24, which isprovided in the outer part 20. The lever 25 is, of itself, supported bya bearing bolt 29, which is placed in an adapter piece 30 between thegear drive housing 3 and an electromagnet 31,

The electromagnet 31 is axis-parallel to the input shaft 1 and issecured on the circumference of the gear drive housing 3 above theadaption piece 30. It possesses magnet coils 32, which surround anarmature 33, which, according to the polarity and amount of currentapplied to the magnet coils 321 is axially displaced and held, in theshift position by means of retaining elements, not further described,for instance, spring loaded ball detents or more advantageously, byform-fit locking magnets. The armature 33 possesses on its end surfacesarmature pins 38, 39 which, coact with the limit switches 36, 37, andmonitor the shifting position, and thereby the function of the shiftingapparatus. In the case of error detection, by means not more closelydescribed here, an alarm is emitted and/or the machine is stopped.

A second arm 27 of the lever 25 is connected in a driving way with thearmature 33, in which said arm extends itself with a rounded head 28through an opening 35 of the magnet coil 32 into a transverse boring 34of the armature 33.

REFERENCE NUMERALS

1 input power shaft

2 output power shaft

3 gear drive housing

4 bearing cover

5 bearing cover

6 roller (or ball) bearing

7 detent

8 coupling part

9 groove

10 spring

11 form-fit connection

12 sun gear

13 planet gear

14 planet bolt

15 planet gear carrier

16 form-fit connection

17 roller (or ball) bearing

18 hollow internal gear

19 slide collar

20 outer part of slide collar

21 inner part of slide collar

22 roller (or ball) bearing

23 holding bolt

24 transverse rod

25 lever

26 arm of lever

27 arm of lever link

28 ball shaped head

29 holding bolt

30 adaption piece

31 electromagnet

32 magnet coil

33 armature

34 transverse boring (armature)

35 opening for 27

36 limit switch

37 limit switch

38 armature pin

39 armature pin

40 come-along toothing

41 coupling component

42 roller (or ball) bearing

43 coupling toothing

44 coupling toothing

What is claimed is:
 1. A two stage planetary gear shifting device havinga sun gear, a planetary carrier (15) supporting a plurality of planetarygears (13), and a hollow internal ring gear (18), the sun gear (12)being connected to an input shaft (1) and the planetary carrier (15)being connected to an output shaft (2) to supply output drive thereto,and the hollow internal ring gear (18) being engageable, via a slidecollar (19), with one of a gear drive housing (3) for the shiftingdevice and the sun gear (12), and the slide collar (19) is coaxiallyslidable, with respect to the input shaft (1), into a plurality of shiftpositions by an electrical positioning member (31); wherein thepositioning member (31) is an electromagnet, the electromagnet (31) hasan armature (33) which is drivingly connected with the slide collar(19), the sliding collar comprises an outer part (20) and the inner part(21) with a bearing (22) located between the outer part (20) and theinner part (21), and the electromagnet (31) has a retaining elementwhich retains the armature (33) in a desired one of the plurality ofshift positions.
 2. The shifting device according to claim 1, whereinthe retaining element is a locking magnet.
 3. The shifting deviceaccording to claim 1, wherein the electromagnet (31) is located about acircumference of the gear drive housing (3) and within an axial lengthof the gear drive housing (3), and the electromagnet (31) extends alongan axis extending parallel to an axis defined by the input shaft (1). 4.The shifting device according to claim 1, wherein a pivoting lever (25)couples the electromagnet (31) to the slide collar (19), and thepivoting lever (25) has one end (27) linked to the armature (33) and anopposite end (26) linked to the slide collar (19).
 5. The shiftingdevice according to claim 4, wherein the outer part (20) of the slidecollar (19) is non-rotatably secured to the gear drive housing (3), by abearing axial bolt (23), which allows axial movement of the slide collar(19) but prevent rotation of the outer part (20) of the slide collar(19).
 6. The shifting device according to claim 4, wherein an adapterpiece (30), to which the pivot lever (25) is supported, is locatedbetween the gear drive housing (3) and the electromagnet (31).
 7. Theshifting device according to claim 4, wherein the armature (33) of theelectromagnet (31) has a transverse bore (34) into which a round head(28), provided on one end (27) of the pivot lever (25), engages.
 8. Theshifting device according to claim 1, wherein the plurality of shiftpositions of the slide collar (19) are monitored by a position sensitiveswitch.
 9. The shifting device according to claim 7, wherein a secondopposed end of the pivot lever (25) has a slot for engaging with a pin(24) which facilitate axial movement of the slide collar (19).
 10. Theshifting device according to claim 9, wherein the engagement between theslot and the pin (24) facilitate pivoting of the pivot lever (25)relative the slide collar (19).
 11. The shifting device according toclaim 7, wherein the pivot lever(25) is pivotally connected to the geardrive housing (3) via a bearing bolt (29) to facilitate pivoting of thepivot lever (25) and actuation of the plurality of shift positions. 12.A two stage planetary gear shifting device having a sun gear, aplanetary carrier (15) supporting a plurality of planetary gears (13),and a hollow internal ring gear (18), the sun gear (12) being connectedto an input shaft (1) and the planetary. carrier (15) being connected toan output shaft (2) to supply output drive thereto, and the hollowinternal ring gear (18) being engageable, via a slide collar (19),withone of a gear drive housing (3) for the shifting device and the sun gear(12), and the slide collar (19) is coaxially slidable,with respect tothe input shaft (1), into a plurality of shift positions by anelectrical positioning member (31); wherein the positioning member (31)is, an electromagnet, the electromagnet (31) has an armature (33) whichis drivingly connected with the slide collar (19), the electromagnet(31) has a retaining element which retains the armature (33) in adesired one of the plurality of shift positions, and a pivoting lever(25) couples the electromagnet (31) to the slide collar (19), and thepivoting lever(25) has one end (27) linked to the armature (33) and anopposite end (26) linked to the slide collar(19).
 13. The shiftingdevice according to claim 12, wherein the retaining element is a lockingmagnet.
 14. The shifting device according to claim 12, wherein theelectromagnet (31) is located about a circumference of the gear drivehousing (3) and within an axial length of the gear drive housing (3),and the electromagnet (31) extends along an axis extending parallel toan axis defined by the input shaft (1).
 15. The shifting deviceaccording to claim 12, wherein the outer part (20) of the slide collar(19) is non-rotatably secured to the gear drive housing (3), by abearing axial bolt (29), which allows axial movement of the slide collar(19) but prevent rotation of the outer part (20) of the slide collar(19).
 16. The shifting device according to claim 12, wherein an adapterpiece (30), to which the pivot lever (25) is supported, is locatedbetween the gear drive housing (3) and the electromagnet (31).
 17. Theshifting device according to claim 29, wherein the armature (33) of theelectromagnet (31) has a transverse bore (34) into which a round head(28), provided on one end (27) of the pivot lever (25), engages.
 18. Theshifting device according to claim 12, wherein the plurality of shiftpositions of the slide collar (19) are monitored by a position sensitiveswitch.
 19. The shifting device according to claim 17, wherein a opposedend of the pivot lever (25) has a slot for engaging with a pin (24)which facilitate axial movement of the slide collar (19).
 20. Theshifting device according to claim 19, wherein the engagement betweenthe slot and the pin (24) facilitate pivoting lever (25) relative theslide collar (19).
 21. The shifting device according to claim 17,wherein the pivot lever (25) is pivotally connected to the gear drivehousing (3) via a bearing bolt (29) to facilitate pivoting of the pivotlever (25) and actuation of the plurality of shift positions.
 22. A twostage planetary gear shifting device having a sun gear, a planetarycarrier (15) supporting a plurality of planetary gears (13), and ahollow internal ring gear (18), the sun gear (12) being connected to aninput shaft (1) and the planetary carrier (15) being connected to anoutput shaft (2) to supply output drive thereto; and the hollow internalring gear (18) being engageable, via a slide collar (19), with one of agear drive housing (3) for the shifting device and the sun gear (12),and the slide collar (19) is coaxially slidable, with respect to theinput shaft (1), into a plurality of shift positions by an electricalpositioning member (31); wherein the positioning member (31) is anelectromagnet, the electromagnet (31) has an armature (33) which isdrivingly connected with the slide collar (19), the sliding collarcomprises an outer part (20) and an inner part (21) with a bearing (22)located between the outer part (20) and the inner part (21), theelectromagnet (31) has a retaining element which retains the armature(33) in a desired one of the plurality of shift positions, and the outerpart (20) of the slide collar (19) is non-rotatably secured to the geardrive housing (3), by a bearing axial bolt (23), which allows axialmovement of the slide collar (19) but prevent rotation of the outer part(20) of the slide collar (19).